Parenting a child on the autism spectrum can be rewarding and enriching, but it may also increase risk of parental fatigue, stress, anxiety, and depression. Parent-mediated interventions contribute to increase family satisfaction and child social communication while helping to decrease parental stress and fatigue. Parent coaching, the education of parents in evidence-based strategies, has become common in the autism field. However, parent coaching in music therapy has only recently emerged and has limited research with families with an autistic member. In this study, we attempted to improve a previously published model of parent coaching, adapting only one aspect of the Early Start Denver Model (ESDM), the sensory social routine (SSR) to create a music intervention. Four parents participated in this 6-session parent coaching study. We compared the SSR-based intervention with and without music, in an alternating treatment design. Measures included parental responsiveness, child receptive and initiation joint attention, parent–child similar affect and synchronized gaze, and the Parent Coaching-ESDM (PC-ESDM) parent fidelity rating system. Results from these observational measures were mixed, with better parental responses in the no-music condition, but improved child responses and parent–child synchrony in the music condition for 3 out of the 4 participants. Parent learning increased for all participants, and 3 out of the 4 reached fidelity (a score of at least 80%), according to the PC-ESDM. Although mixed results were observed across participants, implications for practice are possible. Better outcome measures of this complex intervention are needed.